Breakdown

Breakdown

What happens to poo and other waste?

Introduction

Decomposers play an important role in the circle of life—without them, waste would just pile up! These activities help students study decomposers, with particular relevance to recycling and sustainability.

Decomposers are made up of the FBI (fungi, bacteria and invertebrates—worms and insects). They are all living things that get energy by eating dead animals and plants and breaking down wastes of other animals. Compostable or biodegradable waste is waste that can be broken down and recycled by these decomposers. In our homes, we can recycle food waste into usable nutrients using worms as decomposers. Decomposers are also used in industrial applications such as oil spill cleanup.

Objectives

• List and identify examples of decomposers and describe their role within a simple food web.
• Describe in simple terms the carbon and nitrogen cycles.
• Differentiate between compostable waste and non-biodegradable waste.
• Outline the effect of oil spills on birds and describe a simple bioremediation strategy.
• Create their own compost bin/worm farm.

Background

Energy enters the food chain from the sun. Producers (e.g. plants) create complex organic substances (essentially food) using energy from sunlight and other materials. Consumers (e.g. animals) get their energy by eating the producers or other consumers. Scavengers and decomposers get their energy by eating dead plants or animals.

Rotting food (or food that’s gone ‘bad’) doesn’t look or smell great but contains a wealth of nutrients, including carbon, nitrogen, and phosphorous. Living organisms require these to create cells and tissues and provide energy for life processes. When a plant or animal dies, those nutrients would remain forever locked in the dead tissues if it weren't for decomposers. The decomposers complete the system, returning essential molecules to the plant producers. There are many kinds of decomposers. Each helps recycle food.

Decomposers (fungi, bacteria, invertebrates such as worms & insects) have the ability to break down dead organisms into smaller particles and create new compounds.

The nutrients that decomposers release into the environment become part of the soil, making it fertile and good for growth. These nutrients become a part of new plants that grow from the fertile soil.

Entire Lesson

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Other Resources

Science World at TELUS World of Science | School Workshop | EnviroChallenge
Science World at TELUS World of Science | Search: The Sara Stern Gallery
Metro Vancouver | Worm Composting Brochure (PDF)
Ask the Answer Worm
Recycling Council of British Columbia | Education
The Bug Lab | Educators

 Looking for a wrap-up activity? Check out SuperGreen Trivia